Hypothymidism is a common disease in certain populations, and often is not diagnosed early because of subtle, non-specific symptoms and signs. The adaptation of the very cost effective and accurate method for screening newborn infants using filter paper dried blood spots (DBS) can be applied to pediatric and adult populations to detect diseases before disability and severe symptoms develop, and to monitor patients during therapy, providing greater cost effectiveness, comparable accuracy and greater patient compliance than found with traditional methods. We developed and validated sensitive and precise methods to measure thyroid stimulating hormone (TSH)and the thyroid antibodies, thyroperoxidase antibodies (TPOAb) and thyroglobulin antibodies (TGAb)in DBS specimens. Specific Aims: We shall collect DBS specimens from the following three populations who are at high risk for the development of autoimmune thyroiditis and hypothyroidism: (a) An elderly population currently Living in Nursing and Personal Care Homes will be screened annually for two years. (b) Mothers at diagnosis of pregnancy, at their routine six week visit and at their one year postpartum visit will be screened because they are at increased risk for hypothyroidism during the first postpartum year, and because there may be a deleterious effect on the unborn child if the mother is hypothyroid during early pregnancy. (c) Patients with insulin dependent diabetes mellitus (IDDM) have a 30 to 40% risk of autoimmune thyroid diseases. We are measuring thyroid antibodies in DBS specimens when blood is collected annually to routinely screen for hypothyroidism or for other tests as part of their routine medical care to determine if the presence of thyroid antibodies can preselect those patients who need annual TSH screening. DBS specimen collection kits will be developed so they can be provided to patients or health care professionals to facilitate the collection and mailing of DBS specimens to a population screening Laboratory for the measurement of TSH and thyroid antibodies. The cost for materials, specimen collection, transportation and testing of the populations can be established and compared to the cost to collect, transport and test serum specimens to measure these same tests. With this information and the data on the prevalence of hypothyroidism and thyroiditis in the three populations studied, we can determine the cost effectiveness of screening adults who are at increased risk for hypothyroidism using an easily collected specimen measured by a very Low cost, accurate method. The results of this study will determine the appropriateness of this screening methodology for the populations at risk. PROPOSED COMMERCIAL APPLICATION: Analogous to the currently mandated, very cost-effective population screening of newborns for genetic and metabolic diseases, screening Large populations of adults can be developed and implemented by regional commercial Laboratories. The cost savings for commercial applications is enhanced by the use of the dried blood spotted filter paper specimen since the patient, relative, friend or health care professional including the physician's office can easily collect the four to eight drops of blood and mail the specimen to the Laboratory at a much Lower cost than the collection and shipment of serum specimens. Screening Large populations and using very inexpensive specimens greatly enhance the cost- effectiveness of the test and the commercial application of this technology.